Lakhdar Brahimi, the man brokering Afghanistan peace talks, has long expressed serious doubts about the prospects of deploying foreign peacekeepers in the country.

Those doubts have once again come to the fore as Afghan leaders meet this week near Bonn to discuss the shape of a transitional government.

Apart from agreeing the shape of Afghanistan's political future, the four delegations have also to decide how to maintain peace so that the interim government has a chance of survival.

But the victorious Northern Alliance has so far refused to accept foreign peacekeepers, and doubts are growing over whether the idea by western countries to send a multilateral force to Kabul is tenable.

"The coalition does not exist. What (Afghans) see is national armies descending on Afghanistan," a senior UN official close to the talks said.

The US has dispatched hundreds of marines to Kandahar, while the UK sent in a small force of troops to secure Kabul's Bagram airport. A contingent of French troops was intended to take up positions in northern Afghanistan. But lacking central command, the efforts have been confused, causing embarrassment at home for the UK and France, who were unable to get many - or any, in the case of France - of their troops into Afghanistan.

All three countries are permanent members of the United Nations Security Council - the body that will decide whether to dispatch a longer-term international peacekeeping operation, or a stabilisation force, into Afghanistan and with what mandate.

Just last week the majority of the 15-member council agreed to the idea, pushed by the US and eventually suggested by Mr Brahimi, of sending a multilateral force with a strong Muslim presence to Afghanistan.

Less than a week later, with the Northern Alliance strongly resisting any foreign force and Iran having added its dissenting voice to the fray, the Security Council seems less sure about the plan.

Most significantly Donald Rumsfeld, the US secretary of defense, this week suggested a peacekeeping force may not be heading to Afghanistan in the near future.

"With respect to a stabilisation force, there's been a good deal of discussion about that and at the present time it is not been felt that a stabilisation force was necessarily necessary," he said. He added that the composition of the force was also not at all sure.

Nevertheless, gaining authorisation for such a force from the Afghan parties still tops Mr Brahimi's agenda in Bonn.

He hopes to persuade the 28 delegates meeting at the Petersberg Palace overlooking Bonn to accept peacekeepers by suggesting the Security Council would consider asking their permission.

It is an offer the world's most powerful international legal body does not make often and that some diplomats on the Security Council expect to be made behind closed doors rather than in a formal resolution.

Mr Brahimi believes the Afghan leaders may be less resistant to a foreign force if two conditions are met, a senior UN official close to the talks explains. The problem of ensuring Afghanistan's peace would become far easier to solve if the leaders managed to agree a transitional government, he said.

"Then it is easier, no-one will be looking over their shoulder fearing that others will accuse them of being a stooge of the foreigners," he said.

That body may then be willing to invite international peacekeepers into Afghanistan if the Security Council requested such an invitation, possibly by adopting a resolution.

"Then maybe, maybe they would agree," Mr Brahimi said. To fulfil the second condition, Mr Brahimi will have to convince the Security Council to make such a request. Russia has already insisted in closed-door meetings of the 15-member group that it must not impose peacekeepers on Afghanistan. Most other countries, including the US, UK and China agree.

The US insists sufficient legal cover already exists to send peacekeepers to Afghanistan, and Mr Rumsfeld's comments this week added to the uncertainty about what kind of force Washington would be willing to sign off on.

But Washington seems to be in agreement with Mr Brahimi - even if for different reasons. The UN envoy still believes the best option would be an all-Afghan force, especially for outside Kabul.

"Contrary to what everybody is saying, (Mr Brahimi) thinks it is not difficult or impossible if you have an agreement (on a transitional administration)," the high-level UN official said.

Whether he is able to secure such an agreement will likely be decided within the next few days in the suburbs of Bonn.